I think it really depends on personal taste. If you like dark sand, get dark sand (There's TMBS and other crushed quartz ideas), if you like white sand go with silica sand (can usually be found as sand blasting sand) and if you want a more mixed color, I like pool filter sand. If you're going live planted, I've heard alot of good about eco complete sand, though it is a bit pricy you could do a 50/50 mix with another sand to cut price down.
If you can find a manufacturing/contractor place near you, they're life savers, I got all my silica at one of them (150 lbs worth) for 15 bucks while pricing it at lowes it would have been around 30. They're also the best when you want to get lots of rocks for like a african cichlid tank.